A Comparative Study of Goldman Applanation Tonometer and Non-Contact Autotonometer in Myopic and Age-Matched Normal Subjects (Code-T0159)

Introduction: Accurate measurement of intraocular pressure (IOP) is essential for diagnosing and managing glaucoma. The Goldman Applanation Tonometer (GAT) is considered the gold standard for IOP measurement, while non-contact autotonometry offers a quick, patient-friendly alternative. Myopia has been linked to variations in IOP readings, making it crucial to compare these devices' performance across different refractive states.

Aims and Objectives:

Aim:

To Compare Intraocular pressure in myopic subjects  measured by Goldmann Applanation tonometer and  noncontact tonometer.

Objectives:

1) To assess whether the non-contact tonometer is the appropriate alternative to Goldmann Applanation tonometer for measuring Intraocular pressure.

2) To assess whether Non contact tonometer and Goldmann Applanation  tonometer can be used as a mass screening for myopic subjects detection.

Methods: A cross-sectional study was conducted on 150 participants, including 75 myopic and 75 age-matched normal subjects. IOP measurements were taken sequentially using both GAT and non-contact autotonometers by the same examiner to minimize variability. The study also analyzed factors like central corneal thickness (CCT) and their influence on IOP readings. Statistical analysis was performed using paired t-tests and Bland-Altman plots to assess agreement.

Results: Preliminary findings suggest that non-contact autotonometers tend to overestimate IOP compared to GAT in both groups, with greater discrepancies observed in myopic subjects. The mean difference in IOP readings was statistically significant (p<0.05). Variability was influenced by higher degrees of myopia and variations in CCT.

Conclusion: While non-contact autotonometers provide convenience, GAT remains more accurate, particularly in myopic subjects. Clinicians should consider refractive status and CCT when interpreting IOP readings from different tonometers.

Keywords: Intraocular pressure, Goldman Applanation Tonometer, non-contact autotonometer, myopia, central corneal thickness, glaucoma diagnosis.